NASA is preparing a flurry of new spacecraft launches, planetary flybys and orbital insertions in the next two years, and is celebrating the “Year of the Solar System” to mark the occasion. Twenty-three months is actually a Martian year, so hey, it works.

The space agency has dozens of missions at any given time, and scientists are always maneuvering some spacecraft into a new orbit or into a new trajectory. But the next two years will see triple the usual amount of activity, NASA says. The second half of 2011 will be as busy, space-wise, as entire decades of the space age, according to Jim Green, NASA’s planetary science director.

October kicks off the special year as the EPOXI satellite pays a visit to yet another comet. Then in November, astrobiologists will launch the fantastically named O/OREOS mission, a shoebox-sized satellite designed to test the durability of life in space. It stands for "Organism/ORganic Exposure to Orbital Stresses" and will harbor a group of molecules and microbes and expose them to solar and cosmic radiation, just to see what happens. Scientists have found organic molecules in interstellar space, so NASA would like to know more about how they survive.

In an added bonus, a small solar sail will hitch a ride on O/OREOS and unfurl in Earth orbit. The NanoSail-D will occasionally reflect a sunbeam back to Earth, causing the first “solar sail flares,” NASA says. NASA has had some huge success with hitchhiker satellites — most notably LCROSS, which confirmed the presence of lots of lunar water.

Other milestones include a new spacecraft’s arrival at Venus; the launch of a solar-powered Jupiter probe; a moon-mapping mission; and more.

“History will remember the period Oct. 2010 through Aug. 2012 as a golden age of planetary exploration,” Green said.